JPH04297713A - Pefuse incinerator with fan-shaped spray type secondary air supply nozzle - Google Patents

Abstract

PURPOSE:To inhibit the generation of an unburnt matter by disposing a secondary air supply nozzle opened in a slit shape so that a nozzle hole forms fan- shaped spray to a combustion chamber. CONSTITUTION:A secondary air supply nozzle 6 is fitted to the inlet-section front wall 2a of a secondary combustion chamber 2 while a nose nozzle hole 8 is directed backward, the nozzle hole 8 is formed in a long slit shape in the horizontal direction, and formed so that the shape of spray forms a fan shape on viewing in a plane, and a plurality of the nozzle holes 8 are arranged in the horizontal direction. A combustion gas can be mixed effectively by increasing the flow rate of secondary air blown in by the nozzle 6 in the refuse incinerator. Since secondary air is blown in by a fan-shaped spray type nozzle, the flow rate of secondary air is decreased when secondary air reaches a nozzle opposed wall 2b even when the flow rate is accelerated, and secondary air does not collide with said wall 2b. Secondary air can be dispersed uniformly, and the promotion of the improvement of combustion and the reduction of an unburnt matter can be attained.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention relates to a waste incinerator used for incinerating municipal waste, industrial waste, etc., and more specifically, the present invention relates to a waste incinerator used for incinerating municipal waste, industrial waste, etc. This article concerns a new structure for waste incinerators that suppresses waste.

[0002] In the description of the drawings, the left side of FIGS. 1 and 5 will be referred to as the front in relation to the front and back.

0003

[Prior Art] In the conventional garbage incinerator shown in FIG.
The secondary air was supplied by several secondary air supply nozzles (5).

In other words, in FIG. 5, the grate type waste incinerator consists of a primary combustion chamber (1), a secondary combustion chamber (2) provided above the primary combustion chamber (1), and a secondary combustion chamber (2) installed above the primary combustion chamber (1). Room (2)
The combustion chamber is equipped with an exhaust gas discharge passage (3) that guides the combustion gas generated in the combustion chamber to an outlet (not shown), and a grate (4) provided within the primary combustion chamber (1). In addition, at the entrance of the secondary combustion chamber (2), there is a front wall (2a
) is provided with a secondary air supply nozzle (5). The nozzle (5) has a normal structure for ejecting gas, and one or more nozzles (5) are arranged side by side in the left-right direction.

The garbage (R) in the hopper (7) is placed on the grate (4) and is combusted by the primary air supplied from below the grate (4). 5) Secondary air is supplied from. Garbage (R)
The combustion gas generated by incinerating the gas rises from the primary combustion chamber (1) and enters the secondary combustion chamber (2) almost straight, as shown by the solid line (A) in Fig. The gas is sent to an exhaust gas treatment device (not shown) through path (3).

[0006]

[Problems to be Solved by the Invention] However, the garbage incinerator equipped with the secondary air supply nozzle (5) having the usual structure as described above has the following problems.

That is, the secondary air supply nozzle (5
), up to a certain stage, increasing the flow velocity of the secondary air will improve the mixing of the secondary air and combustion gas within the combustion chamber (2). However, if the flow velocity of the secondary air is increased too much beyond a predetermined value, the secondary air collides with the wall opposite the front wall (2a) where the secondary air supply nozzle (5) is installed, that is, the rear wall (2b). However, secondary air rises along the rear wall (2b). Therefore, it is not possible to obtain a sufficient combustion gas mixing effect, and it is difficult to achieve complete combustion.

As a result of the above, unburned substances such as carbon monoxide, hydrocarbons, and soot are discharged together with the exhaust gas. The large amount of hydrocarbons contained in the exhaust gas are so-called dioxin precursors, and there is a problem in that they react with chlorides such as hydrogen chloride gas in the wake, producing highly toxic dioxins.

[0009] An object of the present invention is to solve the above-mentioned problems and to provide a waste incinerator that can prevent the generation of unburned waste when incinerating municipal waste, industrial waste, etc. in the waste incinerator. be.

0010

[Means for Solving the Problems] The present invention has been devised to achieve the above object, and mixes combustion gas by arranging a secondary air supply nozzle of a specific structure in the combustion chamber. This was completed based on the knowledge that it can be done effectively.

That is, the present invention is characterized in that a secondary air supply nozzle whose nozzle opening is opened in the form of a slit so as to form fan-shaped spray is disposed in the combustion chamber.
It is a garbage incinerator.

[0012] The slit-shaped nozzle is preferably provided so that the shape of the spray is fan-shaped when viewed from above.

In the present invention, it is preferable that a plurality of the secondary air supply nozzles are arranged in a row in the left-right direction on the front wall of the inlet of the combustion chamber, for example, the secondary combustion chamber.

[0014] In addition to the secondary air alone, a mixed gas of secondary air and water, secondary air and steam, or secondary air and recirculation gas can be flowed through the secondary air nozzle.

[0015]

[Operation] In the waste incinerator of the present invention, secondary air is blown into the combustion chamber by the fan-shaped spray nozzle, so that
Even if the air blowing velocity is increased, two
When the next air reaches the wall, its flow velocity is attenuated and no collision occurs with the same wall. Furthermore, the secondary air can be uniformly dispersed over the dispersion surface, promoting combustion improvement and reducing unburned matter.

[0016]

[Embodiments] Next, the present invention will be specifically explained with reference to illustrated embodiments.

FIGS. 1, 2 and 3 show an example of a waste incinerator according to this invention.

The front wall (2a) of the inlet of the secondary combustion chamber (2)
), the secondary air supply nozzle (6) is connected to the tip nozzle (8).
is installed facing towards the rear. The spout (8) of the nozzle (6) is formed in the shape of a horizontally long slit.

A plurality of secondary air supply nozzles (6) are arranged horizontally in parallel in the left-right direction.

[0020] In addition to the secondary air alone, a mixed gas of secondary air and water, secondary air and steam, or secondary air and recirculation gas can be flown through the secondary air nozzle (6).

The other configurations in the figure are the same as those in FIG. 5, so the same components are designated by the same reference numerals and the explanation will be omitted.

[0022] In this garbage incinerator, the nozzle (6)
By increasing the flow velocity of the secondary air blown in, the combustion gases can be mixed effectively. In addition, as shown in Figures 1, 2, and 3, the spray forms a fan shape on the horizontal plane, and the secondary air can be uniformly dispersed on the dispersion plane, promoting improved combustion. can.

In such a configuration, the CO concentration in the exhaust gas at the outlet of the secondary combustion chamber was measured while changing the secondary air blowing flow rate. The measurements were conducted under conditions such that the secondary combustion chamber inlet temperature was 920 to 950°C and the oxygen concentration in the exhaust gas was 6 to 8%. For comparison,
Similar measurements were conducted in the conventional garbage incinerator shown in FIG.

The results of these measurements are shown in FIG.

As is clear from FIG. 4, in the conventional waste incinerator shown in FIG. In the waste incinerator of Example 1 shown in Example 1, the CO concentration decreases significantly as the secondary air blowing flow rate increases.

[0026]

According to the waste incinerator of the present invention, even if the secondary air blowing flow velocity is increased as described above, the flow velocity attenuates when the secondary air reaches the opposing wall of the nozzle.
No collisions occur on the same wall. Further, the secondary air can be uniformly dispersed on the dispersion surface. As a result, it is possible to promote combustion improvement and reduce unburned matter.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view showing one specific example of a waste incinerator according to the present invention.

FIG. 2 is a plan cross-sectional view showing a fan-shaped spray type secondary air supply nozzle installed in the waste incinerator of FIG. 1;

FIG. 3 is a sectional view taken along line III-III in FIG. 2;

FIG. 4 is a graph showing the relationship between the secondary air blowing flow rate and the CO concentration in exhaust gas.

FIG. 5 is a vertical sectional view showing a conventional garbage incinerator.

[Explanation of symbols]

(1)…Primary combustion chamber (2)…Secondary combustion chamber (4)...Grate (5)…Secondary air supply nozzle

Claims (1)

[Claims] 1. A waste incinerator, characterized in that a secondary air supply nozzle having a slit-shaped nozzle opening to form a fan-shaped spray is disposed in a combustion chamber.